A long time ago, during a Lean Manufacturing Training Session, I was taught that if you change something before measuring it, you won’t be able to tell whether or not the change actually improved it. The ideal situation is that you measure, make a single change, measure again and decide whether or not your change made an improvement. The operative word is “single”.
How many of us have the luxury of actually repeating the process of implementing changes and then documenting and analyzing the results? For those in production environments, I’d bet only a small percentage. I’m a controls guy, so I like to measure and analyze things. I also read everything I can get my hands on regarding best practices and OEE (Overall Equipment Effectiveness) measurements and implementations. The notion of “kid in a candy store” is me with OEE data and a plant full of equipment.
Consider this question: Which road will get you to the 60 mile mark faster: Traveling on a road at 30 miles per hour with no traffic lights, or on a road at 50 miles per hour with traffic lights every 4.75 miles, on average, with each red light averaging 2.5 minutes duration? Many of us focus on the minimization problem, and the elementary math, but what’s described in the problem are “ideal” conditions. What we don’t know are the incidences of backups, or the synchronization of the traffic lights.
Ditto that for plant conditions, where few processes are independent. Measuring the performance of one process requires isolating it from the others, such that a fair analysis can be conducted. Also, as in the road problem above, the “better road” will change from one to the other as conditions change.
We need to arm ourselves with information that allows us to make good decisions before the time has expired. Properly implemented, OEE is one tool that will help us make those decisions, since we will understand the inter-relationships of the various processes much better.
By itself OEE isn’t enough. We need to create the culture where changes are embraced. Achieving the overall good is what we want. How fast the production lines ran is far less important than the throughput at the end of the day, with the reject rate factored in. OEE will give you the numbers, but the changes necessary to improve those numbers comes from—you guessed it—you.
Written by Chief Electrical Engineer Jack Chopper
Find him on Twitter: @JackChopper